The CPS-1500 has similar range to the 1000/2500/3000, but its water stream seems not to be as consistent.
It holds more water than the 1000 and is therefore bulkier. Due to its size it cannot normally be used as a backup, though some people actually do.
It boasts two nozzle settings, the 5 times conserving water and having the better range, the 10 times having the sole purpose of getting people wet.
It seems to drain its pressure tank a bit more quickly than the CPS-1000.